"Ah, the good ol' days." "They just don't make [X] like they used to." "Back in my day..."

The wealth of English phrases about how great things used to be might be a tip-off that our quirky ape brains are biased toward looking toward at the past in a happy light. And indeed, many psychologists have seen just that in their research.

Now they're finding that we also seem to look at the future with a positive bias, which coincides with the idea that thinking about the future and remembering the past are similar processes. A group of psychologists led by Harvard's Karl Spzunar have investigated our optimistic forecasting by testing people's memories of events that haven't actually happened. First they asked subjects to recall 100 different memories and then provide some facts for each: where it happened, who was there, whether it was happy or sad, etc.

A week later, the researchers saw how well the subjects could remember false memories: they jumbled the facts together into new combinations, and then tested how well they remembered the details of these contrived stories both 10 minutes and an hour later. After 10 minutes, the subjects could remember the both the positive and negative stories pretty well. But after one day, the positive "memories" stuck in their heads much better—the rose-colored lenses had already kicked in. In fact, the positive feelings may really be sticky, as described by Scientific American:

These findings are consistent with what is known about negative memories for actual past events, which also tend to fade more rapidly than positive ones. Szpu­nar and his colleagues hypothesize that the emotion associated with a future simulation is the glue that binds together the details of the scenario in memory. As the negative emotion dissipates, so, too, does the integrity of the remembered future.

One question that comes up in my mind, and which this research doesn't address, is whether people have a different view of their own personal future and the future of the world. People seem pretty pessimistic about the world as a whole; it's going to hell in a handbasket, as they say. I suspect there are different psychological processes—and different bias—involved with the "memories" of our own personal and global futures.